Ethylene Diamine Disuccinate Research Articles

СOMPLEXES OF Nd(III) AND 3d-METALS BASED ON ETHYLENEDIAMINEDISUCCINIC ACID AS POTENTIAL ANTIFUNGAL AGENTS

Neodymium heterometallic complexes [(NdМIIEDDS)(H2O)6]∙n2H2O (МII=Zn, Co; n = 3; 2) were synthesized by the «block» synthesis method using protonated ethylenediaminedisuccinate of the 3-d metal and NdIII nitrate. The complexes were characterized by spectroscopic methods (UV-VIS electronic absorption spectroscopy and FT-IR) and elemental ana­lysis. It is shown that the f-d-complexes belong to the «folded» type complexes, in which the ligand-EDDS realizes the maximum dentateness to NdIII, and the coordination sphere of the 3-d cation is formed by chain carboxyl groups of EDDS and intraspherical water molecules. At the same time, the cations of 3d metals are in a distorted octahedral environment, and the coordination polyhedron of the neodymium ion corresponds to a square antiprism (C4v) with the coordination number NdIII = 8. In solutions and in the solid state, the complexes have the same type of structure. The sensitivity of various morphological forms of Candida albicans in Spider and Saburo media to neodymium complexes NdIII with ethylene diamine disuccinate: NdEDDS (I), NdEDDSZn (II) NdEDDSСo (III) in the range of concentrations of the studied compounds 1; 10 and 100 μM was studied. It is shown that the antifungal properties of the complexes vary in the range NdEDDSСo> NdEDDSZn ≥ NdEDDS. The inhibition index of C. albicans in the composition of the biofilm in the Saburo medium under the action of the complexes was 20–25% of the control value, and in the Spider medium the complexes led to 95% of cell death.

Phosphonated Iminodisuccinates-A Calcite Scale Inhibitor with Excellent Biodegradability.

Scale inhibitors are an extremely important chemical in upstream oil and gas field operations and water treatment industries. These inhibitors prevent nucleation and/or crystal growth of scales such as calcite and barite. This keeps the pipes and other equipment and surfaces free from deposits, allowing the maximum flow of aqueous fluids. However, many classes of scale inhibitors are poorly biodegraded, especially in seawater, making them unacceptable in regions with strict environmental regulations. Tetrasodium iminodisuccinate (TSIDS) is a biodegradable, industrial-scale dissolver that we imagined could have potential as a scale inhibitor, given the correct derivatization. We first synthesized phosphonated derivatives of TSIDS (TSIDS-P) and the homologue phosphonate made from ethylenediamine disuccinate (TSEDAS-P). In particular, TSIDS-P was shown to be a good calcite scale inhibitor with good calcium compatibility but also exhibited over 70% biodegradation (BOD28) in the OECD 306 seawater test. This should make TSIDS-P a readily biodegradable scale inhibitor of great interest to the petroleum and water treatment industries.

Comparison of synthetic and organic biodegradable chelants in augmenting cadmium phytoextraction in Solanum nigrum

This study focused to enhance the cadmium (Cd) phytoextraction efficiency in Solanum nigrum by applying four biodegradable chelants (10 mM)-ethylene glycol tetraacetic acid (EGTA), ethylenediamine disuccinate (EDDS), nitrilotriacetic acid (NTA), and citric acid (CA), when grown in Cd-spiked soil (12 and 48 mg kg−1). Plant height, dry biomass, photosynthetic traits, and metal accumulation varied significantly with Cd and chelant treatments. Cadmium-toxicity resulted in reduction of plant growth and photosynthetic physiology, whereas chelant supplementation alleviated the toxic effect of Cd and increased its accumulation. Tolerance index value increased with addition of chelants in the order: EGTA (1.57–1.63) >EDDS (1.39–1.58) >NTA (1.14–1.50) >CA (1–1.22) compared with Cd (0.46–1.08). Transfer coefficient of root increased with supplementation of EGTA (3.40–3.85), EDDS (3.10–3.40), NTA (2.60–2.90), and CA (1.85–2.29), over Cd-alone (1.61–1.63). Similarly, translocation factor was also increased upon addition of EGTA (0.52–0.73), EDDS (0.35–0.81), NTA (0.38–0.75), and CA (0.53–0.54), compared with Cd-alone (0.36–0.59). Maximum Cd removal (67.67% at Cd12 and 36.05% at Cd48) was observed with supplementation of EGTA. The study concludes that the supplementation of EGTA and EDDS with S. nigrum can be employed as an efficient and environmentally safe technique for reclamation of Cd-contaminated soils.

Biodegradable chelant-metal complexes enhance cadmium phytoextraction efficiency of Solanum americanum.

Toxic contaminants (metals and metal-containing compounds) are accumulating in the environment at an astonishing rate and jeopardize human health. Remarkable industrial revolution and the spectacular economic growth are the prime causes for the release of such toxic contaminants in the environment. Cadmium (Cd) is ranked the 7th most toxic compound by the Agency for Toxic Substances and Disease Registry (USA), owing to its high carcinogenicity and non-biodegradability even at miniscule concentration. The present study assessed the efficiency of four biodegradable chelants [nitrilotriacetic acid (NTA), ethylenediamine disuccinate (EDDS), ethylene glycol tetraacetic acid (EGTA), and citric acid (CA)] and their dose (5mM and 10mM) in enhancing metal accumulation in Solanum americanum Mill. (grown under 24mg Cd kg-1 soil) through morpho-physiological and metal extraction parameters. Significant variations were observed for most of the studied parameters in response to chelants and their doses. However, ratio of root and shoot length, and plant height stress tolerance index differed non-significantly. The potential of chelants to enhance Cd removal efficiency was in the order - EGTA (7.44%) > EDDS (6.05%) > NTA (4.12%) > CA (2.75%). EGTA and EDDS exhibited dose-dependent behavior for Cd extraction with 10mM dose being more efficient than 5mM dose. Structural equation model (SEM) depicted strong positive interaction of metal extraction parameters with chelants (Z-value = 11.61, p = 0.001). This study provides insights into the importance of selecting appropriate dose of biodegradable chelants for Cd extraction, as high chelant concentration might also result in phytotoxicity. In the future, phytoextraction potential of these chelants needs to be examined through field studies under natural environmental conditions.

Assessment of biodegradable chelating agents in the phytoextraction of heavy metals from multi–metal contaminated soil

A pot incubation experiment under natural conditions was designed to investigate the effects of three biodegradable chelating agents, namely; the [S,S]-isomer of ethylenediamine disuccinate (EDDS), citric acid (CA), and tetrasodium N,N-Bis(carboxymethyl)-L-glutamate acid (GLDA), on two plant species (Brassica juncea and Brassica rapa) in terms of plant foliar growth, dry matter yield, and heavy metal (HM) accumulation. Both plant species exhibited diminished growth and symptoms of phytotoxicity under HM stress. The application of EDDS and CA affected plant foliar growth, biomass production, and led to the development of chlorotic lesions on leaves. EDDS and CA also decreased the shoot length by 38.5% and 45.2% in B. juncea, and 60.1% and 100% in B. rapa, respectively. In contrast, GLDA relieved HM stress by significantly increasing plant growth (P > 0.05) and was shown to be well tolerated (tolerance index [TI]; B. juncea = 99% and B. rapa = 123%). Among both plants, B. juncea displayed the ability to accumulate a wider range of HMs at higher concentrations. Amongst the three chelators, EDDS induced the highest bioconcentration (BCF) of Pb (2.45), Zn (2.68), and Cd (3.36) while CA achieved better results for Ni (4.01) and Cr (1.45). However, the current results showed that even with the application of chelating agents, HMs were predominantly accumulated in roots and translocation factor was generally <1. The findings of this investigation emphasize that chelate–assisted phytoextraction with Brassica spp. is highly limited in multi–metal settings, making it an unsuitable option for severely contaminated sites.

Levels of induced free proline in chelated and unchelated hydroponically grown lettuce (&lt;i&gt;Lactuca sativa L.&lt;/I&gt;)

It is well described that under stress conditions many plant species accumulates proline as adaptive response to adverse conditions. In this study, eight weeks old Lactuca sativa L. seedlings were transplanted in nutrient solution containing various doses (0.000, 0.0025, 0.005, 0.0075, and 0.025mg/L) of Pb2+ and Cd2+ and constant concentration of EDDS (0.0025M). The effects of these treatments of Pb2+, Cd2+, combination of Pb2+ + Cd2+and with or without EDDS (Ethylene diamine disuccinate) were compared based on the level of stress induced to the seedlings. Free proline contents induced due to stress by uptake of Pb2+and Cd2+ were investigated in both unchelated and chelated treatment. The results obtained showed that the effect of increasing concentration of Pb2+ in hydroponic solution leads to decrease in the level of stress induced to the seedlings by EDDS while the lower the Cd2+ concentration in the hydroponic solution the more the level of stress induced by EDDS to the plant. The highest level of stress caused to the seedlings by unchelated and chelated Pb2+ solution are 68.294±5.642; 72.681±14.740 µmolg-1 respectively while that of Cd2+ are 28.962±8.703; 48.263±2.455 µmolg-1 respectively. From this, it is evident that Pb2+induced more stress to the plants than Cd2+ in the presence and absence of EDDS (p&lt;0.05).&#x0D; Keywords: Proline, Ethylenediaminedisuccinic Acid (EDDS), Lead, Cadmium, Lettuce.

Effects of Ethylene Diamine Disuccinic Acid (EDDS) on lead (Pb2+) and cadmium (Cd2+) uptake by lettuce (&lt;I&gt;Lactuca sativa L.&lt;/I&gt;) seedlings planted in hydroponic solutions

This research work was carried out to investigate the effects of ethylene diamine disuccinate (EDDS) on the absorption of cadmium and lead by hydroponically grown lettuce (Lactuca sativa L.). Samples were prepared through digestion (dry ashing) method and the analytes quantitatively analyzed using Atomic Absorption Spectrophotometric (AAS) technique. The effects of EDDS on Pb2+ and Cd2+ uptake by lettuce (Lactuca sativa L.) seedlings replanted in hydroponic solutions for 72 hr in a greenhouse were investigated. Two months old seedlings were exposed to various doses of Pb2+ and Cd2+ at constant concentration of EDDS. For unchelated treatments, increase in concentrations of Pb2+ and Cd2+ in the solution increases the uptake by the plants relative to control. Pb2+ contents in the roots showed more accumulation than in shoots (p&lt;0.05) while Cd2+ content in the shoots was higher than in roots. Addition of 0.0025M EDDS to the solutions of Pb2+ and Cd2+ inhibits the uptake of the metal ions at the following concentrations (0.0025, 0.005 and 0.0075 mg/L) when compared to unchelated treatments of same concentrations. At 0.025 mg/L of Pb2+ and Cd2+, chelation substantially enhances their uptakes in both shoot and root of the plant (p&lt;0.05). Compared to the unchelated treatments, chelation suppresses the translocation of Pb2+ and Cd2+ to the shoots of the plant (p&lt;0.05), but there was a better translocation of Pb2+ (1.257) and Cd2+ (0.953) at 0.025 mg/L, thus indicating that, at very high concentration of the metals the plant was hyper-accumulator. For hydroponic solutions containing the combination of both metals; Pb2+ + Cd2+, Pb2+ uptake was more in the roots than in the shoots while Cd2+ content in the shoots showed more absorption than the roots for both chelated and unchelated treatments. Also, it was observed that chelation suppresses the uptake of Pb2+ and Cd2+ in the presence of one another by both root and shoot. Furthermore, increasing the concentrations of Pb2+ + Cd2+ in chelated treatments of hydroponic solutions results to a better translocation of Pb2+ while the translocation of Cd2+ to the shoot was enhanced. Generally, addition of EDDS to the hydroponic mixtures affected to a large extent the availability of Pb2+ and Cd2+ to the growing seedlings.&#x0D; Keywords: Ethylene diamine disuccinate, greenhouse, hydroponic solution, lettuce, metals.&#x0D;

Phytoremediation of uranium and cadmium contaminated soils by sunflower (Helianthus annuus L.) enhanced with biodegradable chelating agents

Applying biodegradable chelating agents to assist in phytoremediation is a promising method to increase the remove efficiency of metal pollutants from contaminated soils. The effects of biodegradable chelating agents on improving the phytoremediation capacity in uranium (U) and cadmium (Cd) contaminated soil was investigated using sunflowers, which were grown in pots containing soil with U and Cd added at 15 mg/kg. After 2 months of growth, citric acid (CA), oxalic acid (OA) and ethylenediamine disuccinate (EDDS) at various concentrations (0, 2.5, 5.0 and 7.5 mmol/kg) were applied. The results showed that plant biomass decreased by 12.12% for shoot and 15.74% for root under U and Cd combined stress. Meanwhile, chelating agent treatments, especially with EDDS, enhanced U and Cd stress in plants by decreasing biomass, inhibiting photosynthesis, and increasing malondialdehyde and H2O2 levels. The U uptake of plants after CA addition was significantly greater than that after OA and EDDS addition. Nevertheless, EDDS addition has better effects on Cd uptake than CA and OA addition. U and Cd remove efficiencies reached the maximum following the application of 5.0 mmol/kg CA and 5.0 mmol/kg EDDS, which were 177.48% and 181.51% higher than that of the control, respectively. Furthermore, the bioavailable U content in soils treated with CA were higher than that in soils treated with EDDS, whereas bioavailable Cd content significantly increased due to EDDS addition. These results suggest that biodegradable chelating agents have significant effects on improving the U and Cd phytoremediation potential of sunflowers.

Leaching Potential of Multi-metal-Contaminated Soil in Chelate-Aided Remediation

Chelates, used to increase the uptake of heavy metals in phytoremediation, can also increase the mobility of metals. If plants fail to uptake or stabilize all the mobilized metals, then subsurface soil or groundwater can be contaminated. Therefore, the type and concentration of chelate used and proper site management are important for chelate-aided phytoremediation. In this study, we evaluated potential metal leaching from the soil after applying three different chelates. The readily soluble and exchangeable metal (RSEM) and plant-available metal (PAM) of Pb, Zn, Cu, Cd, and Ni in soil amended with ethylene diamine tetra acetic acid (EDTA), ethylene diamine disuccinate (EDDS), or humic acid (HA) were analyzed, and the potential leaching factor (PLF) of the heavy metals was estimated. Results showed that the effects of chelates and their concentration on RSEM and PAM of heavy metal in soil were different. The addition of EDTA increased the CRSEM and CPAM of all heavy metals, although its effects varied with the concentration added. EDDS application increased CRSEM and CPAM of Cu, Ni, and Zn, but EDDS was more effective than EDTA for Cu and Ni. HA did not show a significant impact due to the short duration of the experiment. In most cases with chelates effects, the increase of RSEM was greater than PAM, and the potential of metal leaching increased. Therefore, application of chelates for remediation of metal-contaminated soil should consider not only the capacity of metal uptake in plants but also the potential metal leaching from the system. Additionally, this process should be accompanied by proper water management to minimize leachate in chelate-aided phytoremediation applications.

A combination of ferric nitrate/EDDS-enhanced washing and sludge-derived biochar stabilization of metal-contaminated soils

In this study, soil washing and stabilization as a two-step soil remediation strategy was performed to remediate Pb- and Cu-contaminated soils from shooting range and railway sites. Ferric nitrate (Fe(NO3)3) and [S,S]-ethylenediamine disuccinate (EDDS) were used as washing agents, whereas three types of sludge-derived biochars and phosphogypsum were employed as soil stabilizers. While Fe(NO3)3 extracted larger amounts of metals compared to EDDS (84% Pb and 64% Cu from shooting range soil; 30% Pb and 40% Cu from railway site soil), it caused severe soil acidification. Both Fe(NO3)3 and EDDS washing enhanced the mobility of residual metals in the two soils, which in most cases could be mitigated by subsequent 2-month stabilization by sludge-derived biochars or phosphogypsum. By contrast, the metal bioaccessibility could only be reduced by soil washing. Nutrient-rich sludge-derived biochar replenished available P and K in both soils, whereas Fe(NO3)3 washing provided available nitrogen (N). Soil amendment enhanced acid phosphatase activity but marginally improved soil dehydrogenase and urease activity in the treated soils, possibly due to the influence of residual metals. This study supported the integration of soil washing (by Fe(NO3)3 or EDDS) with soil stabilization (by sludge-derived biochars or phosphogypsum) for accomplishing the reduction of metal mobility and bioaccessibility, while restoring the environmental quality of the treated soils.

Reclamation of Cr-contaminated or Cu-contaminated agricultural soils using sunflower and chelants.

Chromium (Cr) and copper (Cu) are pollutants with a strong environmental impact. "Green biotechnology" as phytoremediation represents a sustainability opportunity for soil reclamation. In this study, we evaluated the possibility to reclaim agricultural soils located in the Solofrana valley, contaminated by Cr or Cu. Chromium contamination derives by repeated flooding events of Solofrana rivers containing Cr because of leather tanning plants, while Cu soil pollution was due to the use of Cu-rich pesticides in agriculture. Both metals showed a very low bioavailability. In order to perform an assisted phytoremediation of polluted fields, we carried out a preliminary ex situ experimentation testing for the first time sunflowers (cv. Pretor) and chelants (ethylenediaminetetraacetic acid (EDTA) and/or ethylene diamine disuccinate (EDDS)), useful when metal bioavailability is low. No symptoms of toxicity were observed in sunflowers grown on both soils, while biomass was improved when EDDS was added. Cr and Cu bioavailability was only slightly enhanced by chelants at the end of the treatments. Both Cr and Cu were mainly accumulated in the roots; moreover, Cu was also translocated to the aboveground organs in the presence of EDTA. The ex situ experimentation demonstrated that assisted phytoremediation is a very slow process not useful in the case of persistent pollution.

EDDS가 바이오에너지 작물의 중금속 흡수에 미치는 영향

ABSTRACT Plants grown in metal-contaminated sites have to be managed and disposed of safely even in phytoremediation becauseheavy metals can be transferred to other organisms through the food chain, which could result in bioaccumulation inorganisms of a higher trophic level. However, if the harvested plants could be used for bioenergy, the ecological risk isreduced and phytoremediation improves economic feasibility. This study researched the effects of EDDS (Ethylenedia-mine disuccinate) on the heavy metal uptake performance of Brassica campetris and Sorghum biocolor, both of whichhave potential as bioenergy plants. The results showed that EDDS could increase Pb, Cu, Ni, Cd, and Zn concentrations inthe roots and shoots of both of these plants. Furthermore, EDDS reduced the metal inhibition of the S. bicolor lengthgrowth. The translocation factors (TF) of S. bicolor and B. campestris are smaller than one for all five heavy metals testedand decreased by the following order: heavy metal + EDDS > heavy metals only > uncontaminated soil. The resultssuggest that with regard to plant growth and metal accumulation, S. bicolor treated with EDDS is more suitable than is B.campestris for the phytoremediation of soils contaminated with multiple metal species.Key words :Phytoremediation, Translocation factor, Brassica campestris, Sorghum bicolor

Selective recovery of indium from lead-smelting dust

Non-ferrous smelting dust, especially lead-smelting dust (LSD), contains percent levels of indium and thus constitutes a novel indium resource. The main difficulty in recovering indium from LSD is the coexisting presence of lead and zinc. In this study, a unique indium separation process was designed, combining techniques that involve washing with a chelant, leaching with acid and precipitation as hydroxide. The majority of the Pb in the LSD was selectively separated during chelant-assisted washing with ethylenediaminedisuccinate (EDDS), while the residual Pb was diminished through an acid leaching treatment with a mixed solution of sulfuric acid and hydrochloric acid. The chelant washing step also ensures a decrease in the raw LSD weight at a ratio of approximately 82% due to the removal of lead and counterions such as sulfate, and the washing step also minimizes the consumption of corrosive acids in the subsequent step. Selective indium separation from LSD is further complicated by the similarity of the behavior of zinc during the acid leaching step. Therefore, hydroxide precipitation at pH 5 has been introduced as the final step, ensuring the maintenance of zinc as a soluble species in the supernatant and the selective separation of indium (∼88%) as a hydroxide precipitate.

Effects of chelates on soil microbial properties, plant growth and heavy metal accumulation in plants

Although chelates can enhance remediation efficiency in phytoremediation, they can cause adverse ecosystem effects. The purpose of this research was to investigate the potential effects of chelating agents on plant and soil ecosystems. The effects of ethylene diamine tetraacetic acid (EDTA), ethylene diamine disuccinate (EDDS), and humic acids (HAs) on soil microbial properties, plant biomass, and metal accumulation were investigated in soils contaminated with Cd, Cu, Pb, Zn, and Ni. Four herbaceous plants were used for experimental purposes: Brassica juncea, Brassica campestris, Sorghum bicolor, and Helianthus annuus. EDTA was most effective for heavy metal uptake by plants, but had significant effects on plants and soils. Although EDDS addition can increase metal uptake, its effects are restricted to some plants and metal species. Plant selection can therefore be a more important factor than use of EDDS. HAs had limited influence on increases in heavy metal uptake but had favorable effects on plants and soil. Decreased plant biomass was strongly related to decreased chlorophyll content caused by increased metal concentrations in plant shoots. Results suggest that more efficient chelates may have higher toxicity. Long-term monitoring is therefore necessary to assess soil quality changes after the addition of chelating agents. Furthermore, the effects of the latter on ecosystems, as well as their metal removal efficiency, should be considered when selecting chelating agents for improved phytoremediation.

Chelator-enhanced phytoextraction of copper and zinc by sunflower, Chinese cabbage, cattails and reeds

The phytoextraction of copper and zinc assisted by the chelators such as ethylene diamine tetraacetic acid, diethylene triamino pentaacetic acid, ethylene diamine disuccinate and citric acid into sunflowers (Hh can act as effective cation exchangers. The negatively charged chelator complexes prevented binding to the cell walls of the roots and allowed complexes to enter the cells. Organic content contains fewer soil nutrients and has fewer negatively charged functional groups, such as carboxical, phenolical and hydroxyl; these adsorb negative free metal cations and reduce metal mobility, leading to less plant uptake. Regardless of different soils’ varying organic content, plant propagation ability can be listed in descending order as follows: cattails > reeds > sunflowers > Chinese cabbage. The mechanism of metal uptake was apoplastic transportation. Metal accumulation levels in different parts of plants are listed in descending order as follows: roots > stems > leaves. This is similar to the findings of most studies.

Biocide Cocktail Consisting of Glutaraldehyde, Ethylene Diamine Disuccinate (EDDS), and Methanol for the Mitigation of Souring and Biocorrosion

Souring and microbiologically influenced corrosion (MIC) caused by sulfate-reducing bacteria (SRB) are major problems in the oil and gas industry as well as other industries such as water utilities. SRB biofilms are notoriously difficult to treat. More effective dosing of biocides is desired to deal with increasing environmental restrictions and costs. This work presents an effective green biocide system consisting of glutaraldehyde (C5H8O2), ethylene diamine disuccinate (EDDS [C10H16N2O8]), and methanol (CH4O) against souring and MIC caused by SRB. Desulfovibrio vulgaris (ATCC 7757) was used in this work in the full strength ATCC 1249 medium and a modified ATCC 1249 medium with only four ingredients (MgSO4, lactate [C3H5O3−], yeast extract, and Fe2+) at concentrations 1/4 of those in the full medium. Tests were carried out in 125 mL anaerobic vials. It was found that the triple combination of 30 ppm (w/w) glutaraldehyde, 1,000 ppm EDDS, and 10% (v/v) methanol was considerably more effective than glutaraldehyde alone and the combination of glutaraldehyde and EDDS in the inhibition of souring, SRB biofilm establishment, and MIC pitting of C1018 carbon steel (UNS G10180) in the presence of 2% (w/w) sand particles in batch tests.

Prenatally detected de novo 46, XX, t(21;21)(p12;p12) at chorionic villus sampling

The continuous increase in industrial activities has contaminated the soil with heavy metals such as cadmium, chromium, copper, mercury, lead, arsenic, nickel, and zinc and are nondegradable and hazardous to life. Many physiochemical methods have been proposed to remove metals from soil, but no method is completely safe and satisfactory. Phytoextraction or phytoaccumulation has emerged as a promising technique for soil remediation that can readily absorb heavy metals and purify the soil of its contaminants. Plants have a natural mechanism to take up and store nutrients according to their bioavailability in soil and the plant’s requirement. Among them, hyperaccumulators have the tendency to take up even nonessential elements by 100-fold greater than nonhyperaccumulators. Because of their larger biomass, they can gather heavy metals using ion channels and metal transport proteins through roots and store them in the above-ground organs where they are either stored in vacuoles and cell walls or detoxified. More than 450–500 plant species have been identified as hyperaccumulators including Thalaspi and Arabidopsis and members from families such as Brassicaceae, Cyperaceae, Poaceae, Fabaceae, and several others. For the plants to effectively take up heavy metal contaminants, the contaminants need to be converted into water-soluble compounds. This technique is called induced phytoextraction in which chelating agents are added in soil that desorb the toxic metals and allow easy uptake by roots. Most common chelates are ethylene diamine tetra acetate, ethylene diamine disuccinate , and other organic acids. However, they can increase toxicity of ground water and affect soil microfauna; therefore, environmental-friendly chelates need to be developed. Another strategy to detoxify soils is to create transgenic plants with increased hyperaccumulation activity against a particular metal. Hence, phytoextraction can be a perfect technique for soil purification because of its minimal limitation. This chapter will focus on the phytoextraction mechanism, metal uptake, and accumulation techniques in plants. Further, the impact of phytoextraction on environmental health will also be explained.

A green triple biocide cocktail consisting of a biocide, EDDS and methanol for the mitigation of planktonic and sessile sulfate-reducing bacteria

Sulfate-reducing bacteria (SRB) cause souring and their biofilms are often the culprit in Microbiologically Influenced Corrosion (MIC). The two most common green biocides for SRB treatment are tetrakis-hydroxymethylphosphonium sulfate (THPS) and glutaraldehyde. It is unlikely that there will be another equally effective green biocide in the market any time soon. This means more effective biocide treatment probably will rely on biocide cocktails. In this work a triple biocide cocktail consisting of glutaraldehyde or THPS, ethylenediaminedisuccinate (EDDS) and methanol was used to treat planktonic SRB and to remove established SRB biofilms. Desulfovibrio vulgaris (ATCC 7757), a corrosive SRB was used as an example in the tests. Laboratory results indicated that with the addition of 10-15% (v/v) methanol to the glutaraldehyde and EDDS double combination, mitigation of planktonic SRB growth in ATCC 1249 medium and a diluted medium turned from inhibition to a kill effect while the chelator dosage was cut from 2,000 to 1,000ppm. Biofilm removal was achieved when 50ppm glutaraldehyde combined with 15% methanol and 1,000ppm EDDS was used. THPS showed similar effects when it was used to replace glutaraldehyde in the triple biocide cocktail to treat planktonic SRB.

The Roles of Diethylenetriamine Pentaacetate (DTPA) and Ethylenediamine Disuccinate (EDDS) in Remediation of Selenium from Contaminated Soil by Brussels Sprouts (Brassica oleracea var. gemmifera)

The objective of this study was to investigate the effects of adding different rates of diethylenetriamine pentaacetate (DTPA) at different concentrations (0, 0.5, 1, and 5 mmol kg−1) and ethylenediamine disuccinate (EDDS) at 0, 5, 7.5, and 10 mmol kg−1 on the capacity of Brussels sprouts plants to take up Se from soils contaminated with 0, 5, 10, and 15 mg kg−1 NaSeO4, under a greenhouse conditions. Results indicated that the application of DTPA and EDDS to Se-contaminated soils significantly affect plant Se concentration, Se uptake, and dry matter yield of plants. Se concentration in the plant leaves, stems, and roots increased with increase in DTPA and EDDS application doses, but total Se uptake increased from 0 to 1.0 and 7.5 mmol kg−1 DTPA and EDDS application doses, respectively, and decreased after those levels due to toxic Se concentration for plant. Most plant available fractions and the carbonate, metal oxide, and organic matter-bound fractions increased linearly with Se application. At all DTPA and EDDS application rates, the Se concentrations in the leaves were about two to three times higher than those in the roots and about three to four times higher than those in the stems. This study suggests that the above-ground organs like leaf and shoots of Brussels sprouts can effectively be used in the removal of Se from soils contaminated with Se. Under the conditions in this experiment, Brussels sprouts were capable of removing 0.9–1.8 mg Se pot−1 when harvested at maturity without any chelating agent take into consideration one growing season per year. Based on the data of present experiment, it would be necessary to approximately 57–67 growing seasons without EDDS and EDTA to remove all total Se from polluted soil. Selenium removal can be further increased 12- to 20-fold with 7.5 mmol kg−1 EDDS and 1.0 mmol kg−1 DTPA application, respectively.

Chelant‐assisted Phytostabilization of Paint‐contaminated Residential Sites

AbstractFollowing the basic incubation study, a greenhouse experiment was conducted to elucidate the efficiency of vetiver grass (Vetiveria zizanioides L.), with or without chelating agents, in remediating lead (Pb)‐contaminated soils from actual residential sites where Pb‐based paints were used. Because the primary factor affecting Pb phytoavailability in soils is soil pH, we used two soil types widely varying in pH that have total Pb concentrations above 1500 mg kg−1 soil. Lead‐contaminated, low pH, acidic soils were collected from residential sites in Baltimore, MD and high pH, alkaline soils were collected from residential sites in San Antonio, TX. Based on the soil characterization results, two most appropriate soils (one from each city, having similar Pb levels but variable soil physico‐chemical properties) were selected for this study. Ethylenediaminetetraacetic acid (EDTA) and [S,S′]ethylenediaminedisuccinate (EDDS) were applied at 5, 10, and 15 mmol kg−1 soil. Lead uptake and translocation in vetiver was determined on day 10 after chelants addition. Plant and soil analysis show that EDTA treated soils have maximum Pb uptake and lower total soil Pb levels. Prediction models developed for exchangeable Pb show a strong correlation for total Pb accumulated in vetiver grass. Results of the sequential chemical extraction of the soils at both initial and final time‐points, indicates a significant mobilization of Pb by the two chelants from carbonate‐bound fraction to exchangeable pool. Information on physico‐chemical properties of contaminated residential soils help in predicting Pb phytoextraction and thus further help in calibrating a successful chelant‐assisted phytoremediation model.